package com.zy.dp.observer.example5;

import java.util.ArrayList;
import java.util.List;

public abstract class WaterQualitySubject
{
	protected List<WatcherObserver> observers = new ArrayList<WatcherObserver>();

	public void attach(WatcherObserver observer)
	{

		observers.add(observer);
	}

	public void detach(WatcherObserver observer)
	{

		observers.remove(observer);

	}

	public abstract void notifyWatchers();

	public abstract int getPolluteLevel();
}
